Hello...
Ok... so you never see a BIOS start up screen... and never get monitor signal verification either, during power up... with this problem.
Well Windows has no control of the BIOS at startup to your motherboard... no software is loaded into your RAM memory... RAM memory is cleared at powerdown... start up is controled by your Hardware and BIOS settings only!!!
Un-Plug your computer from the wall too determine if your power supply/computer/RAM/motherboard is fully powering down... suggest 3-5 minutes.
Since you are un-plugging and plugging in your cable to your graphics card? and getting good results... I would suggest trying a different or new cable... or removing the video card... alcohol clean the connector pins... and reseating the video card...
If you don't have a BIOS boot screen... then something in the hardware is not allowing the motherboard to continue to the video part of the boot sequence... sometimes a beep sequence will tell you what is missing ( do you have your case motherboard speaker hooked up? )... and tell you where in the sequence... the Bios failed to continue.
Now you mentioned Hybernation... well yes there are many problems with certain motherboard Mftr BIOS... with the WIN7 return from hibernation mode? But this is not a computer Boot problem... This is a Return from Hybernation problem... is this what you are experiencing?
Other hardware problems that would cause a motherboard not to Boot would be...
1) A system or CPU fan not being detected by the motherboard... are fans turning?
2) Ram memory not being detected... or timing setting are not correct... start system with 1 stick of memory to explore.
3) Another hardware card could be bad... remove all cards and boot with just video card to explore.
4) Video card could be intermittant... Do you have another video card to swap out?
5) Video cable could have a bad pin... Do you have another cable to swap out?
6) There are multi-power connections to the motherboard... check re-seat connections.
post edited by IronSound - 2010/11/15 13:19:12